The invention is particularly suitable for cut-pile carpet. Cut-pile carpet is characterized by a surface formed by standing pile threads in the form of (cut) thread ends which are connected to a carrier (or backing) mechanically or by means of adhesives.
Carpet tiles are typically manufactured by cutting wide carpet on a roll.
Classical production techniques include tufting and weaving.
In tufting the pile loops are formed by way of a “needle-hook” system. A hook holds the yarn fast once the needle has punched the yarn through a woven or non-woven carrier (primary backing). The thus formed loops can optionally be cut with a knife. A loop-pile carpet or a cut-pile carpet is thus created. In order to prevent the pile threads from being easily pulled out, an additional treatment process after the tufting will adhere the pile threads to the rear side of the carrier using an adhesive. An additional carrier (secondary backing) is then arranged in order to increase the comfort of a tufted carpet.
Drawbacks of tufting are: (1) different operations are necessary after the tufting for the purpose of anchoring the pile yarns and improving the comfort; (2) the limitation of the carrier material used; (3) very limited patterning options because the yarn has to remain in the needle during the tufting. Special techniques (cross-over technique) for improving the patterning then have a very adverse effect on the consumption of pile yarn; (4) there is a “pile direction” corresponding to the production direction; (5) tufting is very susceptible to stripe forming; (6) different layers are necessary in the backing in order to obtain stability (different materials are moreover particularly necessary for manufacturing tiles, which makes recycling of carpet tiles very difficult); and (7) very large “latexing ovens” which eat up energy are necessary for drying and curing the backings.
Characteristic for weaving is the use of warp yarns, weft yarns as well as pile yarns. During the weaving process both the “pile” and the “bottom cloth” of the woven carpet are formed. The pile yarns are anchored by warp yarns and weft yarns being woven into the bottom cloth. Before (axminster technique) or immediately after (face-to-face and wilton techniques) the pile yarns are woven in, the pile material is cut to length, whereby a cut-pile carpet is formed. Following weaving the reverse side of the woven carpet is treated with an additional finish.
In “face-to-face weaving” two carpets which are connected together with the pile threads are woven at the same time. The “non-active” invisible pile threads are woven into the reverse side. The “active” pile threads which connect the two carpets together are then cut with a knife.
In “wilton carpet” the carpet pile is formed by means of metal wires which also determine the pile height. The thus formed loops are woven into the bottom cloth. The woven-in pile loops can optionally be cut, thereby resulting in a cut-pile or loop-pile carpet.
In “axminster carpet” the pile yarns to be woven in are first cut to length and then woven in, whereby they have fewer pile yarns on the rear side of the carpet.
Drawbacks of weaving are: (1) slow production process which causes heavy vibrations (machines have to be built on vibration-free concrete bases); (2) very large and expensive machines; (3) high loss of pile yarns due to the fact that non-active threads (colours) continue to run and are woven into the “back” (underside) of the carpet; (4) there is a pile direction corresponding to the production direction; (5) extra operation to finish the back (pile anchoring) in large latexing ovens which eat up energy; (6) carpets still have to be cut and hemmed to prevent fraying of the edges; (7) a plurality of raw materials in one carpet and particularly the latex for anchoring the pile results in difficult and incomplete recycling; and (8) complicated and not very flexible planning, with loss of bottom cloth, in planning of loose-laid carpet on the four meter-wide machines. The dimensions of loose-laid carpet are also standardized, resulting in a limited supply.
The closest prior art, of which the present invention is also a further development, is EP 0943715 (of Inventor). EP 0943715 describes a yarn-drum applicator used as cylindrical pile thread holder. A primary backing comes to lie against the outer side of the drum applicator. The pile thread holder comprises a plurality of pile thread guide channels perforated on the outer side of the pile thread holder in a matrix pattern. Pile threads are inserted via the outer side of the drum applicator and right through the backing so as to thus form the pile yarn of the pile carpet, wherein the pile ends are protected by the pile guide channels. The part of the pile yarn which has to be fixed in J-Shape to the backing protrudes on the outer side.
Since the backing lies around the drum on the outer side of the cylindrical wall and the pile threads are also introduced from outside, all pile yarns must pass wholly through the backing in order to be carried into the guide channels of the pile thread holder. This can often cause damage to the pile yarn.
A problem is that for the purpose of obtaining a cut-pile carpet only a single thread can be inserted so as to be finally fixed in J-shape between two backings. Arranging V-pile is all the more difficult, if not impossible with this method. The two V-ends have to be arranged here through the backing and into the pile guide channels. This is only possible if the V-pile were to be inserted in reverse direction, wherein the tip of the V-pile is partially sheared afterwards. Furthermore, the chance of damage to the pile yarn is then even greater.